A Science Column Essay Example | Topics and Well Written Essays - 1000 words

A Science Column - Essay Example A physical quantity is defined by the sequence of operations used to determine its value (Wiliamson). The grouping of several physical quantities to find out the values of each in relation to each other is what constitutes a physical law which is defined as. The laws of thermodynamics relate the heat with temperature changes in materials of different kinds. To be clearer on this, let us begin by defining the various laws of thermodynamics. To begin with the first laws which states that Heat is a form of energy, and energy is conserved (Wiliamson). Here the first law confirms that heat is a form of energy and that it can be conserved. This is seen when we use electricity in our homes, the electrical energy is usually stored in the form of water which is then used to drive turbines hence generating electricity which we often use in our homes. This can always be conserved to minimize wastages by either conserving the water stored in a dam or switching off the electricity when not in use . The second law of thermodynamics can be stated in three different ways as defined by three different scholars. For our study we are going to use the definition of Kelvin which states that No cyclic process exists which produces no other effect than the extraction of heat from a body and its conversion into an equivalent amount of work (Wiliamson). The second law of thermodynamics here brings out the reversibility of thermodynamic processes, that is heat is never lost to the surrounding environments given that all factors such as heat loss to the surroundings through evaporation and other heat transfer processes are under control. This is always carried out in the laboratory by using a calorimeter, a laboratory instrument which is used to measure the amount of heat generated through chemical reactions and other physical changes. The calorimeter is designed for this purpose as it is made in such a way that it can minimize heat loss to the surrounding environment as well as heat gain from the same thus ensuring that heat contained in the materials is the same that is used in the entire experiment. It was upon the realization of the limiting factors in the definition of the term temperature by the two thermodynamic laws that the Zeroth law was devised the help in bridging the gap that was omitted. The zeroth law suggests that If two systems are in thermal equilibrium with a third system, then they are in equilibrium with each other (Wiliamson). This law enables one to order systems according to the direction of heat flow when these two systems are put into contact with each other. For this reason, a system is said to be hotter if heat flows from it into the other system which in this case is considered a colder one than the other when these two systems are put into contact with each other. The reverse is however true in the other direction. The third law of thermodynamics on the other and explains that the entropy of a system approaches a constant value as the t emperature approaches absolute zero (Wiliamson). This law suggests that all motions in a material tend to come a standstill, cease within that particular material as the temperature of that material reduces to absolute zero. All materials however must reach a state whereby the temperatures reduce to absolute zero hence no thermodynamic motions occurring within them. The three laws of